Process of producing impregnated irregular paving



Sept. 22, 1931. H. AEBLY 1,324,524

PROCESS OF PRODUCING IMPR EGNATED IRREGULAR PVING Filed Jan. 5. 1929 Patented Sept, 22, 19 31 UNITED STATES HANS AEBLY, or zumorrfswrrzrmrhnn I rnocnss or PRODUCING IMrRnenA'r-nn mammal time Application filed January 5, 1929, Serial No. 330,676,:andinfiwitaerland January 1Q, Q1928.

broken stones are placed in coarse aggregate.

The rough road is then rolled, covered with aggregate, poured over with cold asphalt and rolled solidafter repeated strewing with aggregate. V

A great inconvenience of this process con sists in the circumstance, that the coarse aggregate serving as foundation for the broken stones, is much too permeable for the cold asphalt owing to the relatively wide intervals between the several small stones. The cold asphalt sinks, in the aggregate, very rapidly down, for the greatest part to the foundation, where it is lost as useless. The 7 rapid sinking down causes further an irregular distribution of thefcold asphalt, which will not be substantially improved even by subsequent rolling, as the latter is incapable to still further move the individual stones of the aggregate. These properties of the coarse aggregate are the reason that the cold asphalt does not arrive or only unsufficiently on the lower sides of the broken stones and on the downwardly inclined sides of the same. The embedding of the broken stones remains therefore imperfect, this being of prejudicial influence upon the durability of the cover.

This invention has for its object, to obviate the inconveniences of the process mentioned by using, instead of the coarse aggregate, sand or a fine material of similar behaviour as support for the irregular paving stones. Cold asphalt soaks only very slowly into moistened and compressed sand, as can be easily proved; it-penetrates into the sand really only at the subsequent rolling owing to the shaking and pressing of the paving stones. The cold asphalt flows therefore at the utmost to the depth up to which the shaking and pressing acts, i. e. to the just desii able depth, a; are seeing awn would mean a lossof this expensive material. The imxtureofsand and coldasphalt forms a viscid paste, *whichat' the pressing carried out in uieusun'mannerijs forced up into the 5 intervals between the paving stones and sucked, down'againi The. coldasphalt plays then the'part ofIaJsliding medium for. the s'a-nd 'particl'es. It has. been found, that the colda'splialt arrives really-also on the lower side of the paving l'ston'esh These, paving stones are therefore enveloped in the desired measure b hardens subsequently;

" embodiment of the invention is illustrated in the" accompanying drawings in Whichf Q j gFig. ishswsuieim reved road pavement in tep pla u' vi ws I a Fig.2 is'a'cross-section of Fig. 1. v

Theoldroad'or the finishedfoundation a is covered with'a layer 6 of'sand about 6 ems; thick." Inthis sand the irregular paving stonescare inserted so that the largest,

and plainest side is on the top.

In this manner an irregular joint system is formed (Fig. 1). Then follows wet rolling for equalizing smaller unevenesses and which at the same time makes the sand rise up to a certain height between the stones. Without waiting for the drying abundant cold asphalt is poured on. Before the setting of the fine dispersing asphalt solution the paving is covered with aggregate, and rolled again.

The rolling serves, on the one hand for 0btaining a good mixing of the cold asphalt with the sand serving as support and, on the other hand, to effect a complete embedding of the paving stones in the mortar which is thus produced. The strewn on aggregate is designed to. prevent smearing of the road roller and to secure a complete filling of 7 joints. After the complete setting of the cold asphalt the sand-asphalt-mixture forms y] the? sand-'asphalt-mortar which a hard, compact filling (Z of the joints, solidly cementing the paving stones andvery resistant against wear. ,The filtering in of water is thereby prevented and also the formation of holes leading to bursting. Of the kinds of cold asphalt those are specially suited which t contain the bituminous substances in colloidal distribution. The advantages of the new process are as follows 1.Utilization of the cheaper sand instead as an embedding foundation for the paving stones of aggregate.

2.Avoiding of losses of cold asphalt from too deep soaking.

3.-More perfect embedding of the paving stones.

4. A greater imperme-ability to water, as the paste-like sand-asphaltortar completely fills the joints.

I claim A method of paving street or road surfaces, which consists in depositing upon the bed of the surface a base layer of sand, laying upon the sand paving stones of irregular form and thereby producing a haphazard arrangement of spaces or joints between the stones, subjecting the stones to rolling pressure to level the stones at the top and to depress the stones in the sand and cause the sand to rise in the spaces or joints to a level between the top and bottom surface of the stones, floating overj the surface cold liquid asphalt in quantity to fillthe oints to the surface level therewith and to form with the sand c a viscous pasty mixture spreading aggregate over the surface before the asphalt sets, and rolling the surface to force the surface asphalt and aggregate down into the joints and to force the pasty mixture of asphalt and sand upward between the stones so as to fill all voids and to form with the aggregate a hard compact filling solidly cementing the stones together.

. In testimony whereof I aflix my signature.

, HANS AEBLY. 

